APA aipamena

(2002). Headway: Intermediate- Upper- Advanced. New York: Mc Graw-Hill.

Chicago Style aipamena

Headway: Intermediate- Upper- Advanced. New York: Mc Graw-Hill, 2002.

MLA aipamena

Headway: Intermediate- Upper- Advanced. New York: Mc Graw-Hill, 2002.

Kontuz: berrikusi erreferentzia hauek erabili aurretik.